Added CMake support for specifying what OpenGL target and features that the OpenSceneGraph build should use.

Added use of the new Cmake generated #define's for optionally compiling parts of the OpenSceneGraph's OpenGL support for the various OpenGL targets

src/osg/LightModel.cpp

@@ -12,8 +12,10 @@
 */
 #include <string.h>
 #include <string>
+
 #include <osg/GL>
 #include <osg/LightModel>
+#include <osg/Notify>
 
 using namespace osg;
 
@@ -48,6 +50,7 @@ LightModel::~LightModel()
 
 void LightModel::apply(State&) const
 {
+#ifdef OSG_GL_FIXED_FUNCTION_AVAILABLE
     glLightModelfv(GL_LIGHT_MODEL_AMBIENT,_ambient.ptr());
 
     static bool s_separateSpecularSupported = strncmp((const char*)glGetString(GL_VERSION),"1.2",3)>=0;
@@ -65,5 +68,8 @@ void LightModel::apply(State&) const
     
     glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER,_localViewer);
     glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,_twoSided);
+#else
+    osg::notify(osg::NOTICE)<<"Warning: LightModel::apply(State&) - not supported."<<std::endl;
+#endif
 }